Introduction to Digital Photography Session 1

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Transcript of Introduction to Digital Photography Session 1

Introduction to Digital PhotographyWhat is a Camera?A camera is a device which can record light. It does so by focusing light on a photosensitive surface using 3 main parts.Different types of camerasCompact Camera, DSLR, EVILExposure & HistogramExposure is the amount of light to which the sensor (or film) is exposed. ISO & Shutter SpeedPutting it all together...Digital SensorLensLight Tight Box

The body connects the digital sensor, lens and keeps all of the components communicating with each other.-The photosensitive surface reacts to light through either a chemical process (film) or an electric one (digital sensor). -Sensors are a grid of several million tiny dots (pixels) and each can remember how much light it received in a given period of time. -There are three important qualities to each sensor: resolution, size and what we can call "quality".-It is an optical device which takes scattered light rays and focuses them neatly on the sensor. -Lenses are often complex, with up to 15 different optical elements serving different roles. -The quality of the glass and the precision of the lens will be extremely important in determining how good the final image is.Focal Length & ApertureFocal length is an actual length, expressed in millimeters -Ultra-wide angle - 14-24mm: Specialized, Landscape/Architecture photographers-Wide angle - 24-35mm: Wide enough for context, but not unnatural, often used by photojournalists, most kit lenses start at 18mm-Normal - 40-75mm: 45-50mm is the most natural lens (similar to human perspective), popular street photographer camera-Mild telephoto - 85-105mm: Prime portrait, longer lens, isolates face from background (uses shallow depth of field)-Medium tele -

120-300mm: Longer lens, landscape, distance-Long and exotic tele - 300-800mm: Specialized lenses for wildlife and sports photographers, complex, expensive, narrow angle of view, require tripodsAperture (aka F-Stop) is the actual diameter of the lens opening. f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22 -the smaller the number after the f, the larger the aperture: more light, less depth of field-the higher the number, the smaller the aperture: less light, more depth of field."f/8 and be there""Photograph" from Greek: "photo" derives from "phos" meaning "light" in English "graph" derives from "graphi" meaning to write or draw. A photograph is thus "light writing."ISO Speed aka Sensitivity-ISO indicates your digital camera’s sensitivity to light. The higher the number, the less light is needed to take a photo that is correctly exposed (not too dark or too light).-ISO corresponds to how fine the image is. -A low ISO will equal finer image quality by letting in less higher quality light. -Increasing the ISO as it gets darker let's in more noise.-amount of time the shutter is open and the sensor/film exposed. -usually expressed in fractions of a second, relatively rare to need durations longer than one second. -The longer the speed, the more light can be recorded, thus higher the exposure-Handheld limits; usually between 1/30 & 1/50-Someone walking at a normal pace will usually appear sharp up to 1/50-Sport photographers tend to use 1/500 to 1/1000 as a base speedShutter SpeedA few last pieces...Metering & ModesAuto & Manual FocusWhite BalanceRAW vs. JPEG

-White balance adjusts the color temperature of the camera. If the camera knows what white is, it will recreate all the other colors accurately.-Turn on AWB (auto-white balance) or white balance every time light conditions change.-All light on scene must have the same color temperature to white balance.Metering is the brains behind how your camera determines the shutter speed and aperture, based on lighting conditions and ISO speed-Multi-zone (also called matrix, evaluative or segment) or spot meteringMemory Cards-Format a card on your camera after uploads-Format instead of deleting when finished-know your point, most cameras use a half click and hold-MF is useful on tripods, low light, wait shots, high speed/sports prediction shot

*Email me your top 5 photos as jpeg images as photo attachments for discussion in the next class. benacka@gmail.com

*Class activity: Look at your camera, set all settings to ISO 600, F8, Focus on the still life. What speed do you need?Next Class:-Lighting, Flash, Natural light...-Image Composition-Photo History-Bring your questions!

Digital SensorLight Tight Box

LensOverexposed: the image is too bright, too much pure white light Underexposed: the image is too dark, not enough light was allowed on the sensor.